Analytical Method
Isotopic measurement techniques evaluating carbon-14 decay ratios establish the age and bio-based proportion of textile materials. In commercial testing, radiocarbon dating measures unstable carbon isotopes to differentiate contemporary plant-derived fibres from fossil-derived synthetic polymers. Unstable carbon-14 isotopes decay at a known rate over a half-life of five thousand seven hundred and thirty years, whereas petroleum-based synthetics contain zero remaining carbon-14.
The scope of this analytical method covers natural fibres, bio-synthetics, recycled yarns, and organic blends, but stops where inorganic mineral coatings or metallic threads dominate sample mass.
Biobased Determination
Modern analytical laboratories utilize accelerator mass spectrometry to count carbon isotopes directly from combusted textile specimens. Standard test methods like ASTM D6866 express bio-based content as a percentage of total organic carbon in the fabric. Through radiocarbon dating, inspectors verify claims that bio-polyester or bio-nylon samples originate from agricultural feedstocks rather than petrochemical precursors.
Laboratory Protocol
Chemical pretreatments remove surface finishes and soil contamination that could alter isotopic carbon counts. Specimen preparation converts organic carbon into graphite targets for mass spectrometer injection during radiocarbon dating procedures. Precise isotope ratio calculations compare sample carbon-14 activity against oxalic acid reference standards.
Testing reports declare the exact percentage of modern bio-based carbon relative to fossil carbon within mixed fibre blends.
Material Boundary
Inorganic dyes do not contain carbon isotopes evaluated during radiocarbon dating.
